cobraperri

AC was working early fall, now it doesn't. The compressor is not coming on. The fuses are all good....even the Over Voltage Relay fuse. Obviously no power to the compressor, because the clutch won't engage even when pushed against when the engine is running.
I checked the grounds...they're fine.
It could be the (AMP??? can't remember the name) back behind the OVR, but the engine runs great with no fuel related problems.
How can I jump the compressor? Which wires?
Shadow, you still out there? Don't really need AC right now, but I want everything working, and I think it's good to run the AC occasionally.
Shadow, come on back.......you the man!!!

cobraperri

What the hecks taking you so long?

hurry up and post my friend!

Gotta go, check it in the morning, see you then Shadow!

cobraperri

MAS not AMP. Could be MAS, how can I check it? How many wires actually go to the AC compressor?

YNVDIZW124

Are you sure the A/C controls are not bad? just an idea

zjamiez

If you jump the two wires together which go into the pressure sensor on the dryer located just behind your drivers side head light.. If it does come on this could be an indication that there is not enough pressure (eg leak somewhere)in the system and it needs to be refilled or that the pressure sensor is bad.. Think mine cost around $30 from mercedes to replace however turns out I had a slow leak!

cobraperri

Excellent guys!
First, I think my AC controls are OK as they still direct the flow to the selected area.
I'm going to go and jump the "low pressure switch" now. I'll be back in 5 minutes.

cobraperri

I jumped the low pressure switch...........no luck
I jumped the switch right next to it........no luck
I pulled the OVR, fuse is still good
Which box is the MAS, the one toward the rear of the car or the one in the front? There are 2 boxes back by the OVR which are about the same size. I'm guessing the front one is the MAS.
The one in the front has the work "KICKDOWN" on it.
Any ideas, thanks guys.

floodkid

I had this problem a while back. Not sure if itll help but it worked for me.

Open up the fuse box, then take off the plate with the fuses on it. and you have a mess of wires. I jiggled the wires around and found that one of the connections in there was loose. tightend a few screws (One was in a lil black box) and cleaned out anything that looked like it wo uld help with some Electrical cleaner.

Good luck

cobraperri

Thanks Flood, I've wiggled and jiggled all the fuses and wires. Had all the fuses out and back in.
I'm leaning toward the MAS, as I've read it's a common problem.
There are 2 connector plugs on the AC compressor. One has 2 wires, the other has 3.
Anyone know which wires powers the clutch? Why so many wires going to the compressor?
Love the good old days when you could put power to AC clutch on the 2 terminals.

cobraperri

TTT
Take it to the top!

bamberger_1

The clutch has 2 wires and in my car one of the wire was rotten. Very hard to find and even worse to replace. The wires enter the clutch on the lower end of it and disappear inside the clutch running through an "insulator block". I guess the best way would be to have the car on a car lift and check from the bottom.